Open AccessRelationship between the Rate of Citrulline Synthesis and Bulk Changes in the Intramitochondrial ATP/ADP Ratio in Rat‐Liver Mitochondria
Author(s) -
WANDERS Ron J. A.,
WOERKOM George M.,
NOOTEBOOM Ron F.,
MEIJER Alfred J.,
TAGER Joseph M.
Publication year - 1981
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1981.tb05066.x
Subject(s) - oligomycin , hexokinase , atp synthase , biochemistry , carbamoyl phosphate synthetase , mitochondrion , atp–adp translocase , adenine nucleotide , chemiosmosis , adenosine triphosphate , adenosine diphosphate , biology , glycolysis , chemistry , nucleotide , inner mitochondrial membrane , atpase , enzyme , platelet , platelet aggregation , gene , immunology
1 The relationship between intramitochondrial and extramitochondrial ATP‐utilizing systems and the intramitochondrial ATP/ADP ratio was studied in isolated rat‐liver mitochondria. Citrulline synthesis was used as an intramitochondrial ATP‐utilizing system, and glucose‐6‐phosphate synthesis as an extramitochondrial ATP‐utilizing system. The intramitochondrial ATP/ADP ratio was manipulated in three ways: with succinate and different concentrations of malonate and/or hexokinase; with 2‐oxoglutarate (plus oligomycin) and different concentrations of hexokinase; and with added ATP in uncoupled mitochondria (oligomycin present). 2 Under all conditions used, citrulline synthesis was strictly correlated with the bulk intramitochondrial ATP/ADP ratio. 3 The curve relating citrulline synthesis and intramitochondrial ATP/ADP was shifted towards lower ATP/ADP ratios when the activity of carbamoyl‐phosphate synthetase was enhanced by increasing the mitochondrial content of N ‐acetylglutamate. 4 It is concluded that under the experimental conditions used the intramitochondrial adenine nucleotides behave as a homogeneous pool.